kdump boot failing with IVRS checksum failure

[Jerry Snitselaar]

Hello Joerg,

We are seeing a kdump kernel boot failure in test on an HP DL325 Gen10
and it was tracked down to 387caf0b759a ("iommu/amd: Treat per-device
exclusion ranges as r/w unity-mapped regions"). Reproduced on 5.9-rc5
and goes away with revert of the commit. There is a follow on commit
that depends on this that was reverted as well 2ca6b6dc8512 ("iommu/amd:
Remove unused variable"). I'm working on getting system access and want
to see what the IVRS table looks like, but thought I'd give you heads
up.

Regards,
Jerry